Fix abd leak, kmem_free correct size of abd_t

Fix a leak of abd_t that manifested mostly when using
raidzN with at least as many columns as N (e.g. a
four-disk raidz2 but not a three-disk raidz2).
Sufficiently heavy raidz use would eventually run a system
out of memory.

Additionally:

* Switch abd_cache arena to FIRSTFIT, which empirically
improves perofrmance.

* Make abd_chunk_cache more performant and debuggable.

* Allocate the abd_zero_buf from abd_chunk_cache rather
than the heap.

* Don't try to reap non-existent qcaches in abd_cache arena.

* KM_PUSHPAGE->KM_SLEEP when allocating chunks from their
own arena

Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Jorgen Lundman <lundman@lundman.net>
Co-authored-by: Sean Doran <smd@use.net>
Closes #12295
This commit is contained in:
Jorgen Lundman 2021-07-02 00:28:15 +09:00 committed by GitHub
parent eca174527e
commit c6d1112bf4
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4 changed files with 10 additions and 6 deletions

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@ -64,7 +64,7 @@ void abd_free_struct(abd_t *);
*/
abd_t *abd_alloc_struct_impl(size_t);
abd_t *abd_get_offset_scatter(abd_t *, abd_t *, size_t);
abd_t *abd_get_offset_scatter(abd_t *, abd_t *, size_t, size_t);
void abd_free_struct_impl(abd_t *);
void abd_alloc_chunks(abd_t *, size_t);
void abd_free_chunks(abd_t *);

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@ -374,14 +374,17 @@ abd_alloc_for_io(size_t size, boolean_t is_metadata)
}
abd_t *
abd_get_offset_scatter(abd_t *abd, abd_t *sabd, size_t off)
abd_get_offset_scatter(abd_t *abd, abd_t *sabd, size_t off,
size_t size)
{
abd_verify(sabd);
ASSERT3U(off, <=, sabd->abd_size);
size_t new_offset = ABD_SCATTER(sabd).abd_offset + off;
uint_t chunkcnt = abd_scatter_chunkcnt(sabd) -
(new_offset / zfs_abd_chunk_size);
size_t chunkcnt = abd_chunkcnt_for_bytes(
(new_offset % zfs_abd_chunk_size) + size);
ASSERT3U(chunkcnt, <=, abd_scatter_chunkcnt(sabd));
/*
* If an abd struct is provided, it is only the minimum size. If we

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@ -835,7 +835,8 @@ abd_alloc_for_io(size_t size, boolean_t is_metadata)
}
abd_t *
abd_get_offset_scatter(abd_t *abd, abd_t *sabd, size_t off)
abd_get_offset_scatter(abd_t *abd, abd_t *sabd, size_t off,
size_t size)
{
int i = 0;
struct scatterlist *sg = NULL;

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@ -531,7 +531,7 @@ abd_get_offset_impl(abd_t *abd, abd_t *sabd, size_t off, size_t size)
}
ASSERT3U(left, ==, 0);
} else {
abd = abd_get_offset_scatter(abd, sabd, off);
abd = abd_get_offset_scatter(abd, sabd, off, size);
}
ASSERT3P(abd, !=, NULL);